Chemical Thermodynamics of Tin - Volume 12 - OECD Nuclear ...

422
A Discussion of selected references
An attempt was made to approximate the high temperature data of Kapustinskii
et al. [1936KAP/ZIL] as well as Gurevich et al.’s data [2004GUR/GAV2] in the
temperature range from 296.90 to 336.88 K with Eq. (A.93). According to Kapustinskii
et al. [1936KAP/ZIL] their C
o ( ) p, m
T function is given by the following Maier and
Kelley equation [1932MAI/KEL]
1496 K.
o
C ( ) p, m
T /J·K –1·mol –1 = a + b·(T/K)+ c·(T/K) –2 (A.92)
Equation (A.92) was used to calculate C
o ( ) , m
T in the range from 595 to
In order to obtain a basis for the calculation of entropy and enthalpy functions
at high temperature the data listed in Table A-73 were approximated by the modified
Eq. (VII-21) as below, see also Figure A-49:
o
o
C
p, m
(calc) – C
p, m
(298.15 K) = a·(T – 298.15) + b·(T 2 – 298.15 2 ) + c·(T –2 – 298.15 –2 )
+ d·(T –3 – 298.15 –3 ) + e·(T –0.5 – 298.15 –0.5 ) + f·(T –1 – 298.15 –1 ). (A.93)
p
Table A-73: Heat capacity of cassiterite SnO 2 (cr) as measured by [2004GUR/GAV2] 1
and calculated according to Eq. (A.92) as recommended by [1936KAP/ZIL] 2 .
T/K
o
C
p, m
/J·K –1·mol –1 T/K
o
–1
C
p, m
/J·K
–1·mol
296.90 55.33 1 331.57 58.12 1
302.33 55.84 1 336.88 58.56 1
307.52 56.29 1 595.15 74.0979 2
312.86 56.61 1 728.15 76.9942 2
318.18 57.12 1 855.85 79.0381 2
323.48 57.67 1 861.55 79.1191 2
328.80 58.14 1 886.45 79.4652 2
334.11 58.65 1 1006.15 80.9853 2
298.26 55.23 1 1009.15 81.0210 2
299.81 55.30 1 1020.65 81.1566 2
305.11 55.80 1 1132.15 82.4063 2
310.40 56.20 1 1187.15 82.9876 2
315.69 56.71 1 1493.15 85.9653 2
320.98 57.17 1 1495.65 85.9884 2
326.27 57.73 1
o
For C
p, m
(298.15 K) the value obtained from the analysis of the low
temperature data was accepted. The fitting parameters of Eq. (VII.25) and Eq. (A.92)
are listed below.
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012